How many supervisory devices can be connected to a single initiating device circuit?

In NFPA 72, the regulations specify limitations on the number of supervisory devices connected to a single initiating device circuit to ensure system reliability and maintainability. Specifically, the code stipulates that a maximum of 20 supervisory devices can be connected to a single initiating device circuit. This limit is established to ensure that each device can be properly monitored and controlled, enhancing the overall effectiveness of the fire alarm system.

By adhering to this maximum, it helps prevent circuit overload and potential failures in the system, thereby ensuring that all connected devices can be reliably monitored for their status (whether they are operational or require attention). Understanding these limitations is essential for designing and implementing compliant and effective fire alarm systems.